For my money, the very best foreign policy blogger on the internet is anonmugwump. One thing he is particularly good at is skewering popular myths. His latest post is one of the best I've read on his blog—an extremely well-sourced and detailed look at five popular myths about ISIS. He shows, in detail, that:

Military intervention probably won't make things worse

The issue isn't predominantly political

ISIS is likely a threat to the West

Intervening isn't a trap

Cutting off ISIS's funding from gulf states isn't the best way to deal with it.

To some extent, the following myths are all interlinked. The typical anti-war activist believes that the current crisis is mainly political and financial and so military means are not addressing the primary cause of the rise of ISIS. The idea that we’re going to make it worse through military intervention isn’t just because its failing to address the key causes but because it reinforces what went wrong: Maliki alienated Sunnis and bombs will alienate Sunnis. And somewhat linked but not entirely, they think because ISIS is a response to local conditions, ISIS is not concerned with attacking the West. This post is addressed to these people – their premises are false and so their conclusions and prescriptions are also flawed.